Raw tiff file from Vuescan looks darker then the one from Silverfast

[Jake]

Why does the raw tiff file created by Vuescan look darker than the raw
tiff file created by Silverfast ai?

I scan a 4 by 6 in. photo at 48HDR and 400dpi with Silverfast, and I
scan it at 48bit RGB and 400dpi with Vuescan. Then I open both on
Photoshop 7, one looks darker than the other. If both are getting the
raw data from the scanner, shouldn't they look the same? Silverfast
does embed 'silverfast' in the image since it's a trial version. Does
that suggest the image is processed.

I wish Vuescan provide a more detailed steps for creating a raw scan
than what it has on its Help. For example, I wonder if scanning twice,
which helps for regular scan as its help suggests, would help in
creating raw tiff files. And should color balance be set to none? Its
default is white balance.

 

[Ken]

Why does the raw tiff file created by Vuescan look darker than the raw
tiff file created by Silverfast ai?

I scan a 4 by 6 in. photo at 48HDR and 400dpi with Silverfast, and I
scan it at 48bit RGB and 400dpi with Vuescan. Then I open both on
Photoshop 7, one looks darker than the other. If both are getting the
raw data from the scanner, shouldn't they look the same? Silverfast
does embed 'silverfast' in the image since it's a trial version. Does
that suggest the image is processed.

Exposure control can still be different, so scans will be different. Vuescan
and Silverfast probably use different algorithms to determine exposure.

I wish Vuescan provide a more detailed steps for creating a raw scan
than what it has on its Help. For example, I wonder if scanning twice,
which helps for regular scan as its help suggests, would help in
creating raw tiff files. And should color balance be set to none? Its
default is white balance.

For RAW scans the color balance settings are irrelevant.

 

[Ed Hamrick]

Exposure control can still be different, so scans will be different.
Vuescan
and Silverfast probably use different algorithms to determine exposure.

It's possible that SilverFast is storing the raw data with a gamma 2.2
applied. This is what VueScan does when the raw file is in 24-bit
format.

It might be worth asking them this question in their support forum.

Regards,
Ed Hamrick